An Ontario man convicted of killing his four-year-old niece is a likely miscarriage of justice, Attorney General Michael Bryant said Friday. He is urging Ottawa to rush a review of the case that should acquit William Mullins-Johnson.

Mullins-Johnson was convicted of murdering his 12-year-old niece Valin but was released after 12 years behind bars. New evidence surfaced that tissue samples capable of showing Valin died of natural causes were lost.

Without that evidence, he was convicted on the strength of pathologist Dr. Charles Smith's conclusion that the young girl was sexually assaulted and strangled.

Mullins-Johnson was released from custody in September 2005.

His case is one of many surfacing in the wake of a public inquiry into Smith's work was called. An expert panel questioned the pathologist's findings in 20 cases, 12 of which resulted in criminal convictions and one of not criminally responsible.

The Ontario government filed papers Friday to support Mullins-Johnson's request for a review of his conviction by the federal justice minister, Bryant told The Canadian Press.

"The Ontario Crown's position is that the conviction in this case cannot stand, and that Mr. Mullins-Johnson should ultimately be acquitted by the Ontario Court of Appeal,'' Bryant said.

"We've obviously come to this position based on a full review of the case including new expert evidence. The expert reports provided by the chief coroner's office have significantly undermined the forensic evidence at trial relating to the circumstances surrounding" Valin's death.

News of the government's support for his cause came as a relief.

"Metaphorically speaking, it was like constantly having a stain of blood splashed on you," Mullins-Johnson said of his ordeal.

Mullins-Johnson hopes he can regain his good name as quickly as possible. His lawyer says it needs to happen soon.

"Give him his name back, because my God, his name was taken through the mud for so many years," James Lockyer said.

The federal justice minister has three options. The case can be referred to the Ontario Court of Appeal, a new trial can be ordered or the government can choose to do nothing.

Bryant and Mullins-Johnson are hoping Ottawa will take the first option.

"Out of respect for the process, I'm saying it's in the hands of the federal minister of justice to decide what to do with the Crown's position in Ontario,'' Bryant said.

Mullins-Johnson could have his good name back in as little as 60 days. But he says that he will never be able to reclaim lost family, friends and 12 years of his life spent in prison.

Bryant has also taken steps to help two other people who were convicted based, at least in part, on evidence provided by Smith.

On Tuesday, the Ontario Crown supported a bail application for Marco Trotta of Oshawa, Ont. He was convicted of second-degree murder in 1998 for the death of his infant son.

Also on Tuesday, Bryant moved to allow Sherry Sherrett of Trenton, Ont. to bring her infanticide conviction to the Ontario Court of Appeal. She spent a year in prison for the 1996 death of her infant son.

Bryant said Friday that government is working on all cases where Smith's evidence has been called into question. Officials want to make sure any other possible miscarriages of justice are quickly dealt with, he added.

"Each of those cases has been assigned a Crown attorney, and I think we've demonstrated that we're ready, willing and able to address these issues as quickly and appropriately as possible," Bryant said.

"Every case is going to be different. I don't think you can point at one case and generalize about it.'"

Bryant said his office is also reviewing the way Crown attorneys deal with expert reports and forensic pathology to "see what we can learn from the chief coroner's report (into Smith's work)."

"We're doing that right now, even before we get the results from the public inquiry."

With a report from CTV's Paul Bliss and files from The Canadian Press